LAMMPS (28 Mar 2023 - Development)
dimension       3
units           micro
atom_style      sph

variable        a equal 0.1             # lattice spacing         micrometers
variable        L equal $a*10
variable        L equal 0.1*10
variable        T equal 300.
variable        kB equal 1.3806504e-8   # picogram-micrometer^2/(microsecond^2-Kelvin)
variable        rho_0 equal 1.          # density                   picograms/micrometer^3
variable        c_0 equal 10.           # speed of sound            micrometers/microsecond
variable        mu equal 1.             # dynamic viscosity         picogram/(micrometer-microsecond)
variable        h equal $a*4.0          # kernel function cutoff    micrometers
variable        h equal 0.1*4.0          
variable        mass equal $a*$a*$a*${rho_0}
variable        mass equal 0.1*$a*$a*${rho_0}
variable        mass equal 0.1*0.1*$a*${rho_0}
variable        mass equal 0.1*0.1*0.1*${rho_0}
variable        mass equal 0.1*0.1*0.1*1
variable        dt equal 5e-4           # timestep                  microseconds
variable        skin equal 0.1*$h
variable        skin equal 0.1*0.4

region          box block -$L $L -$L $L -$L $L units box
region          box block -1 $L -$L $L -$L $L units box
region          box block -1 1 -$L $L -$L $L units box
region          box block -1 1 -1 $L -$L $L units box
region          box block -1 1 -1 1 -$L $L units box
region          box block -1 1 -1 1 -1 $L units box
region          box block -1 1 -1 1 -1 1 units box
create_box      1 box
Created orthogonal box = (-1 -1 -1) to (1 1 1)
  1 by 2 by 2 MPI processor grid
lattice         sc $a
lattice         sc 0.1
Lattice spacing in x,y,z = 0.1 0.1 0.1

create_atoms    1 box
Created 8000 atoms
  using lattice units in orthogonal box = (-1 -1 -1) to (1 1 1)
  create_atoms CPU = 0.001 seconds

mass            * ${mass}
mass            * 0.001
set             group all sph/rho ${rho_0}
set             group all sph/rho 1
Setting atom values ...
  8000 settings made for sph/rho

pair_style      sdpd/taitwater/isothermal $T ${mu} 76787    # temperature viscosity random_seed
pair_style      sdpd/taitwater/isothermal 300 ${mu} 76787    
pair_style      sdpd/taitwater/isothermal 300 1 76787    
pair_coeff      * * ${rho_0} ${c_0} ${h}
pair_coeff      * * 1 ${c_0} ${h}
pair_coeff      * * 1 10 ${h}
pair_coeff      * * 1 10 0.4

variable        vx_sq atom vx*vx
variable        vy_sq atom vy*vy
variable        vz_sq atom vz*vz
compute         v_sq all reduce ave v_vx_sq v_vy_sq v_vz_sq
variable        vx_sq_check equal c_v_sq[1]*${mass}/${kB}/$T
variable        vx_sq_check equal c_v_sq[1]*0.001/${kB}/$T
variable        vx_sq_check equal c_v_sq[1]*0.001/1.3806504e-08/$T
variable        vx_sq_check equal c_v_sq[1]*0.001/1.3806504e-08/300
variable        vy_sq_check equal c_v_sq[2]*${mass}/${kB}/$T
variable        vy_sq_check equal c_v_sq[2]*0.001/${kB}/$T
variable        vy_sq_check equal c_v_sq[2]*0.001/1.3806504e-08/$T
variable        vy_sq_check equal c_v_sq[2]*0.001/1.3806504e-08/300
variable        vz_sq_check equal c_v_sq[3]*${mass}/${kB}/$T
variable        vz_sq_check equal c_v_sq[3]*0.001/${kB}/$T
variable        vz_sq_check equal c_v_sq[3]*0.001/1.3806504e-08/$T
variable        vz_sq_check equal c_v_sq[3]*0.001/1.3806504e-08/300

fix             1 all sph

neighbor        ${skin} bin
neighbor        0.04 bin
timestep        ${dt}
timestep        0.0005

thermo          10
thermo_style    custom step time v_vx_sq_check v_vy_sq_check v_vz_sq_check

run             200
Generated 0 of 0 mixed pair_coeff terms from geometric mixing rule
Neighbor list info ...
  update: every = 1 steps, delay = 0 steps, check = yes
  max neighbors/atom: 2000, page size: 100000
  master list distance cutoff = 0.44
  ghost atom cutoff = 0.44
  binsize = 0.22, bins = 10 10 10
  1 neighbor lists, perpetual/occasional/extra = 1 0 0
  (1) pair sdpd/taitwater/isothermal, perpetual
      attributes: half, newton on
      pair build: half/bin/atomonly/newton
      stencil: half/bin/3d
      bin: standard
Per MPI rank memory allocation (min/avg/max) = 6.172 | 6.172 | 6.172 Mbytes
   Step          Time      v_vx_sq_check  v_vy_sq_check  v_vz_sq_check 
         0   0              0              0              0            
        10   0.005          0.71224819     0.71470372     0.7008956    
        20   0.01           0.90627589     0.90683966     0.90116506   
        30   0.015          0.938505       0.95884272     0.93337542   
        40   0.02           0.94394649     0.93668038     0.96468004   
        50   0.025          0.97152309     0.97546161     0.95107762   
        60   0.03           0.94710871     0.95678322     0.97285504   
        70   0.035          0.96253148     0.95838642     0.95450883   
        80   0.04           0.97581495     0.95278681     0.95099478   
        90   0.045          0.96251614     0.9740684      0.96081505   
       100   0.05           0.94191275     0.97137523     0.94084858   
       110   0.055          0.953406       0.95739684     0.98574522   
       120   0.06           0.99001614     0.99608287     0.9839996    
       130   0.065          0.96575225     0.94309655     0.92847798   
       140   0.07           0.97642687     0.97458638     0.94696406   
       150   0.075          0.99316381     0.96876814     0.95440106   
       160   0.08           0.94589744     0.95264791     0.95495169   
       170   0.085          0.97599092     0.95336014     0.97687718   
       180   0.09           0.97214242     0.9726305      0.9726035    
       190   0.095          0.97577583     0.96523645     0.9756968    
       200   0.1            0.96386053     0.97268854     0.94582436   
Loop time of 9.59181 on 4 procs for 200 steps with 8000 atoms

Performance: 900768.333 ns/day, 0.000 hours/ns, 20.851 timesteps/s, 166.809 katom-step/s
98.1% CPU use with 4 MPI tasks x no OpenMP threads

MPI task timing breakdown:
Section |  min time  |  avg time  |  max time  |%varavg| %total
---------------------------------------------------------------
Pair    | 8.9729     | 9.2147     | 9.4383     |   5.5 | 96.07
Neigh   | 0          | 0          | 0          |   0.0 |  0.00
Comm    | 0.13739    | 0.36068    | 0.60216    |  27.6 |  3.76
Output  | 0.0022724  | 0.002394   | 0.0026506  |   0.3 |  0.02
Modify  | 0.0068559  | 0.0069926  | 0.0070974  |   0.1 |  0.07
Other   |            | 0.007004   |            |       |  0.07

Nlocal:           2000 ave        2000 max        2000 min
Histogram: 4 0 0 0 0 0 0 0 0 0
Nghost:           8469 ave        8469 max        8469 min
Histogram: 4 0 0 0 0 0 0 0 0 0
Neighs:         364000 ave      376628 max      351184 min
Histogram: 1 0 1 0 0 0 0 1 0 1

Total # of neighbors = 1456000
Ave neighs/atom = 182
Neighbor list builds = 0
Dangerous builds = 0
Total wall time: 0:00:09
